Hair straightening iron



FIG. 1 is a side view of the hair straightening iron;

FIG. 2 is a top view of the hair straightening iron;

FIG. 3 is a bottom view of the hair straightening iron;

FIG. 4 is a front view of the hair straightening iron;

FIG. 5 is a rear view of the hair straightening iron; and,

FIG. 6 is a perspective view of the hair straightening iron. 

The ornamental design for a hair straightening iron, as shown, and described. 